what would make my car run great sitting still but die when you put it in gear on 1990 Oldsmobile Cutlass Supreme

when never you try and move it usually dies but if it runs it has no getup or go put the car in reverse and she will move anywhere,i have put new tps,map sensor,new fuel pump,newfuel filter,new plugs and wires,i have run out of things to putback new,new ign,new coil packs,took the injectoers and put new seals and such also,they done a test that says delayed timing,now they say needs new timing chain what's could be next,can anybody help me

i had the same issue and replaced the same exaxt things..i finally took it to a great mechanic and he found 4 shorted injactors. i replaced all 6 with rebuilt ones and the car is running great. i saw where you replaced the injector seals. but check for shorted unjectors. hope this helps.